Commit 8db4c5be authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso
Browse files

netfilter: move socket lookup infrastructure to nf_socket_ipv{4,6}.c



We need this split to reuse existing codebase for the upcoming nf_tables
socket expression.
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 1fddf4ba
#ifndef _NF_SOCK_H_
#define _NF_SOCK_H_
struct net_device;
struct sk_buff;
struct sock;
struct net;
static inline bool nf_sk_is_transparent(struct sock *sk)
{
switch (sk->sk_state) {
case TCP_TIME_WAIT:
return inet_twsk(sk)->tw_transparent;
case TCP_NEW_SYN_RECV:
return inet_rsk(inet_reqsk(sk))->no_srccheck;
default:
return inet_sk(sk)->transparent;
}
}
struct sock *nf_sk_lookup_slow_v4(struct net *net, const struct sk_buff *skb,
const struct net_device *indev);
struct sock *nf_sk_lookup_slow_v6(struct net *net, const struct sk_buff *skb,
const struct net_device *indev);
#endif
......@@ -25,6 +25,12 @@ config NF_CONNTRACK_IPV4
To compile it as a module, choose M here. If unsure, say N.
config NF_SOCKET_IPV4
tristate "IPv4 socket lookup support"
help
This option enables the IPv4 socket lookup infrastructure. This is
is required by the iptables socket match.
if NF_TABLES
config NF_TABLES_IPV4
......
......@@ -14,6 +14,8 @@ obj-$(CONFIG_NF_NAT_IPV4) += nf_nat_ipv4.o
# defrag
obj-$(CONFIG_NF_DEFRAG_IPV4) += nf_defrag_ipv4.o
obj-$(CONFIG_NF_SOCKET_IPV4) += nf_socket_ipv4.o
# logging
obj-$(CONFIG_NF_LOG_ARP) += nf_log_arp.o
obj-$(CONFIG_NF_LOG_IPV4) += nf_log_ipv4.o
......
/*
* Copyright (C) 2007-2008 BalaBit IT Ltd.
* Author: Krisztian Kovacs
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/skbuff.h>
#include <net/tcp.h>
#include <net/udp.h>
#include <net/icmp.h>
#include <net/sock.h>
#include <net/inet_sock.h>
#include <net/netfilter/nf_socket.h>
#if IS_ENABLED(CONFIG_NF_CONNTRACK)
#include <net/netfilter/nf_conntrack.h>
#endif
static int
extract_icmp4_fields(const struct sk_buff *skb, u8 *protocol,
__be32 *raddr, __be32 *laddr,
__be16 *rport, __be16 *lport)
{
unsigned int outside_hdrlen = ip_hdrlen(skb);
struct iphdr *inside_iph, _inside_iph;
struct icmphdr *icmph, _icmph;
__be16 *ports, _ports[2];
icmph = skb_header_pointer(skb, outside_hdrlen,
sizeof(_icmph), &_icmph);
if (icmph == NULL)
return 1;
switch (icmph->type) {
case ICMP_DEST_UNREACH:
case ICMP_SOURCE_QUENCH:
case ICMP_REDIRECT:
case ICMP_TIME_EXCEEDED:
case ICMP_PARAMETERPROB:
break;
default:
return 1;
}
inside_iph = skb_header_pointer(skb, outside_hdrlen +
sizeof(struct icmphdr),
sizeof(_inside_iph), &_inside_iph);
if (inside_iph == NULL)
return 1;
if (inside_iph->protocol != IPPROTO_TCP &&
inside_iph->protocol != IPPROTO_UDP)
return 1;
ports = skb_header_pointer(skb, outside_hdrlen +
sizeof(struct icmphdr) +
(inside_iph->ihl << 2),
sizeof(_ports), &_ports);
if (ports == NULL)
return 1;
/* the inside IP packet is the one quoted from our side, thus
* its saddr is the local address */
*protocol = inside_iph->protocol;
*laddr = inside_iph->saddr;
*lport = ports[0];
*raddr = inside_iph->daddr;
*rport = ports[1];
return 0;
}
static struct sock *
nf_socket_get_sock_v4(struct net *net, struct sk_buff *skb, const int doff,
const u8 protocol,
const __be32 saddr, const __be32 daddr,
const __be16 sport, const __be16 dport,
const struct net_device *in)
{
switch (protocol) {
case IPPROTO_TCP:
return inet_lookup(net, &tcp_hashinfo, skb, doff,
saddr, sport, daddr, dport,
in->ifindex);
case IPPROTO_UDP:
return udp4_lib_lookup(net, saddr, sport, daddr, dport,
in->ifindex);
}
return NULL;
}
struct sock *nf_sk_lookup_slow_v4(struct net *net, const struct sk_buff *skb,
const struct net_device *indev)
{
__be32 uninitialized_var(daddr), uninitialized_var(saddr);
__be16 uninitialized_var(dport), uninitialized_var(sport);
const struct iphdr *iph = ip_hdr(skb);
struct sk_buff *data_skb = NULL;
u8 uninitialized_var(protocol);
#if IS_ENABLED(CONFIG_NF_CONNTRACK)
enum ip_conntrack_info ctinfo;
struct nf_conn const *ct;
#endif
int doff = 0;
if (iph->protocol == IPPROTO_UDP || iph->protocol == IPPROTO_TCP) {
struct udphdr _hdr, *hp;
hp = skb_header_pointer(skb, ip_hdrlen(skb),
sizeof(_hdr), &_hdr);
if (hp == NULL)
return NULL;
protocol = iph->protocol;
saddr = iph->saddr;
sport = hp->source;
daddr = iph->daddr;
dport = hp->dest;
data_skb = (struct sk_buff *)skb;
doff = iph->protocol == IPPROTO_TCP ?
ip_hdrlen(skb) + __tcp_hdrlen((struct tcphdr *)hp) :
ip_hdrlen(skb) + sizeof(*hp);
} else if (iph->protocol == IPPROTO_ICMP) {
if (extract_icmp4_fields(skb, &protocol, &saddr, &daddr,
&sport, &dport))
return NULL;
} else {
return NULL;
}
#if IS_ENABLED(CONFIG_NF_CONNTRACK)
/* Do the lookup with the original socket address in
* case this is a reply packet of an established
* SNAT-ted connection.
*/
ct = nf_ct_get(skb, &ctinfo);
if (ct && !nf_ct_is_untracked(ct) &&
((iph->protocol != IPPROTO_ICMP &&
ctinfo == IP_CT_ESTABLISHED_REPLY) ||
(iph->protocol == IPPROTO_ICMP &&
ctinfo == IP_CT_RELATED_REPLY)) &&
(ct->status & IPS_SRC_NAT_DONE)) {
daddr = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip;
dport = (iph->protocol == IPPROTO_TCP) ?
ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.tcp.port :
ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.udp.port;
}
#endif
return nf_socket_get_sock_v4(net, data_skb, doff, protocol, saddr,
daddr, sport, dport, indev);
}
EXPORT_SYMBOL_GPL(nf_sk_lookup_slow_v4);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Krisztian Kovacs, Balazs Scheidler");
MODULE_DESCRIPTION("Netfilter IPv4 socket lookup infrastructure");
......@@ -25,6 +25,12 @@ config NF_CONNTRACK_IPV6
To compile it as a module, choose M here. If unsure, say N.
config NF_SOCKET_IPV6
tristate "IPv6 socket lookup support"
help
This option enables the IPv6 socket lookup infrastructure. This
is used by the ip6tables socket match.
if NF_TABLES
config NF_TABLES_IPV6
......
......@@ -24,6 +24,8 @@ obj-$(CONFIG_NF_NAT_MASQUERADE_IPV6) += nf_nat_masquerade_ipv6.o
nf_defrag_ipv6-y := nf_defrag_ipv6_hooks.o nf_conntrack_reasm.o
obj-$(CONFIG_NF_DEFRAG_IPV6) += nf_defrag_ipv6.o
obj-$(CONFIG_NF_SOCKET_IPV6) += nf_socket_ipv6.o
# logging
obj-$(CONFIG_NF_LOG_IPV6) += nf_log_ipv6.o
......
/*
* Copyright (C) 2007-2008 BalaBit IT Ltd.
* Author: Krisztian Kovacs
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/skbuff.h>
#include <net/tcp.h>
#include <net/udp.h>
#include <net/icmp.h>
#include <net/sock.h>
#include <net/inet_sock.h>
#include <net/inet6_hashtables.h>
#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
#include <net/netfilter/nf_socket.h>
#if IS_ENABLED(CONFIG_NF_CONNTRACK)
#include <net/netfilter/nf_conntrack.h>
#endif
static int
extract_icmp6_fields(const struct sk_buff *skb,
unsigned int outside_hdrlen,
int *protocol,
const struct in6_addr **raddr,
const struct in6_addr **laddr,
__be16 *rport,
__be16 *lport,
struct ipv6hdr *ipv6_var)
{
const struct ipv6hdr *inside_iph;
struct icmp6hdr *icmph, _icmph;
__be16 *ports, _ports[2];
u8 inside_nexthdr;
__be16 inside_fragoff;
int inside_hdrlen;
icmph = skb_header_pointer(skb, outside_hdrlen,
sizeof(_icmph), &_icmph);
if (icmph == NULL)
return 1;
if (icmph->icmp6_type & ICMPV6_INFOMSG_MASK)
return 1;
inside_iph = skb_header_pointer(skb, outside_hdrlen + sizeof(_icmph),
sizeof(*ipv6_var), ipv6_var);
if (inside_iph == NULL)
return 1;
inside_nexthdr = inside_iph->nexthdr;
inside_hdrlen = ipv6_skip_exthdr(skb, outside_hdrlen + sizeof(_icmph) +
sizeof(*ipv6_var),
&inside_nexthdr, &inside_fragoff);
if (inside_hdrlen < 0)
return 1; /* hjm: Packet has no/incomplete transport layer headers. */
if (inside_nexthdr != IPPROTO_TCP &&
inside_nexthdr != IPPROTO_UDP)
return 1;
ports = skb_header_pointer(skb, inside_hdrlen,
sizeof(_ports), &_ports);
if (ports == NULL)
return 1;
/* the inside IP packet is the one quoted from our side, thus
* its saddr is the local address */
*protocol = inside_nexthdr;
*laddr = &inside_iph->saddr;
*lport = ports[0];
*raddr = &inside_iph->daddr;
*rport = ports[1];
return 0;
}
static struct sock *
nf_socket_get_sock_v6(struct net *net, struct sk_buff *skb, int doff,
const u8 protocol,
const struct in6_addr *saddr, const struct in6_addr *daddr,
const __be16 sport, const __be16 dport,
const struct net_device *in)
{
switch (protocol) {
case IPPROTO_TCP:
return inet6_lookup(net, &tcp_hashinfo, skb, doff,
saddr, sport, daddr, dport,
in->ifindex);
case IPPROTO_UDP:
return udp6_lib_lookup(net, saddr, sport, daddr, dport,
in->ifindex);
}
return NULL;
}
struct sock *nf_sk_lookup_slow_v6(struct net *net, const struct sk_buff *skb,
const struct net_device *indev)
{
__be16 uninitialized_var(dport), uninitialized_var(sport);
const struct in6_addr *daddr = NULL, *saddr = NULL;
struct ipv6hdr *iph = ipv6_hdr(skb);
struct sk_buff *data_skb = NULL;
int doff = 0;
int thoff = 0, tproto;
tproto = ipv6_find_hdr(skb, &thoff, -1, NULL, NULL);
if (tproto < 0) {
pr_debug("unable to find transport header in IPv6 packet, dropping\n");
return NULL;
}
if (tproto == IPPROTO_UDP || tproto == IPPROTO_TCP) {
struct udphdr _hdr, *hp;
hp = skb_header_pointer(skb, thoff, sizeof(_hdr), &_hdr);
if (hp == NULL)
return NULL;
saddr = &iph->saddr;
sport = hp->source;
daddr = &iph->daddr;
dport = hp->dest;
data_skb = (struct sk_buff *)skb;
doff = tproto == IPPROTO_TCP ?
thoff + __tcp_hdrlen((struct tcphdr *)hp) :
thoff + sizeof(*hp);
} else if (tproto == IPPROTO_ICMPV6) {
struct ipv6hdr ipv6_var;
if (extract_icmp6_fields(skb, thoff, &tproto, &saddr, &daddr,
&sport, &dport, &ipv6_var))
return NULL;
} else {
return NULL;
}
return nf_socket_get_sock_v6(net, data_skb, doff, tproto, saddr, daddr,
sport, dport, indev);
}
EXPORT_SYMBOL_GPL(nf_sk_lookup_slow_v6);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Krisztian Kovacs, Balazs Scheidler");
MODULE_DESCRIPTION("Netfilter IPv6 socket lookup infrastructure");
......@@ -1426,9 +1426,10 @@ config NETFILTER_XT_MATCH_SOCKET
tristate '"socket" match support'
depends on NETFILTER_XTABLES
depends on NETFILTER_ADVANCED
depends on !NF_CONNTRACK || NF_CONNTRACK
depends on IPV6 || IPV6=n
depends on IP6_NF_IPTABLES || IP6_NF_IPTABLES=n
depends on NF_SOCKET_IPV4
depends on NF_SOCKET_IPV6
select NF_DEFRAG_IPV4
select NF_DEFRAG_IPV6 if IP6_NF_IPTABLES != n
help
......
......@@ -22,76 +22,14 @@
#include <net/netfilter/ipv4/nf_defrag_ipv4.h>
#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
#define XT_SOCKET_HAVE_IPV6 1
#include <linux/netfilter_ipv6/ip6_tables.h>
#include <net/inet6_hashtables.h>
#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
#endif
#include <net/netfilter/nf_socket.h>
#include <linux/netfilter/xt_socket.h>
#if IS_ENABLED(CONFIG_NF_CONNTRACK)
#define XT_SOCKET_HAVE_CONNTRACK 1
#include <net/netfilter/nf_conntrack.h>
#endif
static int
extract_icmp4_fields(const struct sk_buff *skb,
u8 *protocol,
__be32 *raddr,
__be32 *laddr,
__be16 *rport,
__be16 *lport)
{
unsigned int outside_hdrlen = ip_hdrlen(skb);
struct iphdr *inside_iph, _inside_iph;
struct icmphdr *icmph, _icmph;
__be16 *ports, _ports[2];
icmph = skb_header_pointer(skb, outside_hdrlen,
sizeof(_icmph), &_icmph);
if (icmph == NULL)
return 1;
switch (icmph->type) {
case ICMP_DEST_UNREACH:
case ICMP_SOURCE_QUENCH:
case ICMP_REDIRECT:
case ICMP_TIME_EXCEEDED:
case ICMP_PARAMETERPROB:
break;
default:
return 1;
}
inside_iph = skb_header_pointer(skb, outside_hdrlen +
sizeof(struct icmphdr),
sizeof(_inside_iph), &_inside_iph);
if (inside_iph == NULL)
return 1;
if (inside_iph->protocol != IPPROTO_TCP &&
inside_iph->protocol != IPPROTO_UDP)
return 1;
ports = skb_header_pointer(skb, outside_hdrlen +
sizeof(struct icmphdr) +
(inside_iph->ihl << 2),
sizeof(_ports), &_ports);
if (ports == NULL)
return 1;
/* the inside IP packet is the one quoted from our side, thus
* its saddr is the local address */
*protocol = inside_iph->protocol;
*laddr = inside_iph->saddr;
*lport = ports[0];
*raddr = inside_iph->daddr;
*rport = ports[1];
return 0;
}
/* "socket" match based redirection (no specific rule)
* ===================================================
*
......@@ -111,104 +49,6 @@ extract_icmp4_fields(const struct sk_buff *skb,
* then local services could intercept traffic going through the
* box.
*/
static struct sock *
xt_socket_get_sock_v4(struct net *net, struct sk_buff *skb, const int doff,
const u8 protocol,
const __be32 saddr, const __be32 daddr,
const __be16 sport, const __be16 dport,
const struct net_device *in)
{
switch (protocol) {
case IPPROTO_TCP:
return inet_lookup(net, &tcp_hashinfo, skb, doff,
saddr, sport, daddr, dport,
in->ifindex);
case IPPROTO_UDP:
return udp4_lib_lookup(net, saddr, sport, daddr, dport,
in->ifindex);
}
return NULL;
}
static bool xt_socket_sk_is_transparent(struct sock *sk)
{
switch (sk->sk_state) {
case TCP_TIME_WAIT:
return inet_twsk(sk)->tw_transparent;
case TCP_NEW_SYN_RECV:
return inet_rsk(inet_reqsk(sk))->no_srccheck;
default:
return inet_sk(sk)->transparent;
}
}
static struct sock *xt_socket_lookup_slow_v4(struct net *net,
const struct sk_buff *skb,
const struct net_device *indev)
{
const struct iphdr *iph = ip_hdr(skb);
struct sk_buff *data_skb = NULL;
int doff = 0;
__be32 uninitialized_var(daddr), uninitialized_var(saddr);
__be16 uninitialized_var(dport), uninitialized_var(sport);
u8 uninitialized_var(protocol);
#ifdef XT_SOCKET_HAVE_CONNTRACK
struct nf_conn const *ct;
enum ip_conntrack_info ctinfo;
#endif
if (iph->protocol == IPPROTO_UDP || iph->protocol == IPPROTO_TCP) {
struct udphdr _hdr, *hp;
hp = skb_header_pointer(skb, ip_hdrlen(skb),
sizeof(_hdr), &_hdr);
if (hp == NULL)
return NULL;
protocol = iph->protocol;
saddr = iph->saddr;
sport = hp->source;
daddr = iph->daddr;
dport = hp->dest;
data_skb = (struct sk_buff *)skb;
doff = iph->protocol == IPPROTO_TCP ?
ip_hdrlen(skb) + __tcp_hdrlen((struct tcphdr *)hp) :
ip_hdrlen(skb) + sizeof(*hp);
} else if (iph->protocol == IPPROTO_ICMP) {
if (extract_icmp4_fields(skb, &protocol, &saddr, &daddr,
&sport, &dport))
return NULL;
} else {
return NULL;
}
#ifdef XT_SOCKET_HAVE_CONNTRACK
/* Do the lookup with the original socket address in
* case this is a reply packet of an established
* SNAT-ted connection.
*/
ct = nf_ct_get(skb, &ctinfo);
if (ct && !nf_ct_is_untracked(ct) &&
((iph->protocol != IPPROTO_ICMP &&
ctinfo == IP_CT_ESTABLISHED_REPLY) ||
(iph->protocol == IPPROTO_ICMP &&
ctinfo == IP_CT_RELATED_REPLY)) &&
(ct->status & IPS_SRC_NAT_DONE)) {
daddr = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip;
dport = (iph->protocol == IPPROTO_TCP) ?
ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.tcp.port :
ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.udp.port;
}
#endif
return xt_socket_get_sock_v4(net, data_skb, doff, protocol, saddr,
daddr, sport, dport, indev);
}
static bool
socket_match(const struct sk_buff *skb, struct xt_action_param *par,
const struct xt_socket_mtinfo1 *info)
......@@ -217,7 +57,7 @@ socket_match(const struct sk_buff *skb, struct xt_action_param *par,
struct sock *sk = skb->sk;
if (!sk)
sk = xt_socket_lookup_slow_v4(par->net, skb, par->in);
sk = nf_sk_lookup_slow_v4(par->net, skb, par->in);
if (sk) {
bool wildcard;
bool transparent = true;
......@@ -233,7 +73,7 @@ socket_match(const struct sk_buff *skb, struct xt_action_param *par,
* if XT_SOCKET_TRANSPARENT is used
*/
if (info->flags & XT_SOCKET_TRANSPARENT)
transparent = xt_socket_sk_is_transparent(sk);
transparent = nf_sk_is_transparent(sk);
if (info->flags & XT_SOCKET_RESTORESKMARK && !wildcard &&
transparent)
......@@ -265,132 +105,7 @@ socket_mt4_v1_v2_v3(const struct sk_buff *skb, struct xt_action_param *par)
return socket_match(skb, par, par->matchinfo);
}
#ifdef XT_SOCKET_HAVE_IPV6
static int
extract_icmp6_fields(const struct sk_buff *skb,
unsigned int outside_hdrlen,
int *protocol,
const struct in6_addr **raddr,
const struct in6_addr **laddr,
__be16 *rport,
__be16 *lport,
struct ipv6hdr *ipv6_var)
{
const struct ipv6hdr *inside_iph;
struct icmp6hdr *icmph, _icmph;